Clutch interlocked circuit breaker carrier mechanism



Jan. 22, 1957 E. E. HEBBEL ET AL 2,778,895

CLUTCH INTERLOCKED CIRCUIT BREAKER CARRIER MECHANISM 2 Sheets-Sheet 1 Filed Oct. 25, 1951 wger e m n w ew w t @mb t .559 .A .n D r e E .I vs! e ne W I m E h C 1957 E. E. HEBBEL ET AL 2,778,895

CLUTCH INTERLOCKED CIRCUIT BREAKER CARRIER MECHANISM Filed Oct. 25, 1951 2 Shets-Sheec 2 Inventors: Charles D. Eicl'welber er, Emil BHebbel,

United States Patent CLUTCH INTERLOCKED CIRCUIT BREAKER CARRIER MECHMISM Emil E. Hebbel, Sharon Hill, and Charles D. Eichelberger, Rldley Park, Pa., assignors to General Electric Com pany, a corporation of New York Application October 25, 1951, Serial No. 253,018

9 Claims. (Cl. 200--50) The invention relates to carrier mechanism for disconnectable circuit breakers, particularly elevating and lowering mechanism for power circuit breakers of the removable metal clad type that are provided with circuit disconnection contacts so as to require some form of safety interlocking for preventing movement of the disconnectable circuit breaker to or from the connected position when the power circuit interrupting contacts of the breaker are closed. Otherwise completion and interruption of the power circuit may occur at the disconnect contacts with disastrous results.

It is quite desirable that such safety interlocking be positively effective whether the disconnectable circuit breaker carrier mechanism is operated by a reversible electric driving motor or manually.

Thus the principal object of the present invention is to provide an improved mechanical clutch interlocked form of circuit breaker carrier mechanism adapted for both electric motor and manual operation and having driving clutch members that must always be moved into engagement for carrying the circuit breaker to and from the connected position and provided with positive mechanical interlocking connections with a locking member for the circuit breaker closing mechanism so as to positively block and thereby prevent the engagement of the driving clutch members whenever the circuit breaker is closed and also positively block and thereby prevent the closure of the circuit breaker whenever the driving clutch members are engaged.

Another object is to provide the improved clutch interlocked form of circuit breaker carrier mechanism with a control switch for enabling the reversible electric driving motor to be clutched and simultaneously energized for carrying the disconnectable circuit breaker to and from the connected position with safety under all operating conditions.

Another object is to provide an improved reversing control for the reversible electric driving motor of the clutch interlocked elevator mechanism whereby movement of the driving clutch members toward engagement will simultaneously close the control switch and initiate operation of the motor only after a manual reversing switch is operated in the proper direction predetermined by suitable limit switches. This efiectively insures against improper operation due to carelessness or inadvertence.

Another object is to provide an improved self-setting creep lock for positively holding the disconnectable circuit breaker carrier mechanism against movement due to jar or vibration when the driving clutch members are disengaged and having means for releasing the creep lock only when the driving clutch members are engaged.

Another object is to provide a special interlocking clutch type of manual operating crank for cooperating with the improved clutch interlocked circuit breaker carrier mechanism in case of removal of the driving motor.

Other objects and advantages of the invention will appear in the following description of the accompanying drawings in which Fig. 1 is a side View of a typical power circuit breaker closed in the elevated or circuit connected ice position inside an enclosing metal cubicle with a side wall thereof broken away to show a preferred construction of the improved clutch interlocked elevating mechanism that can be driven by a reversible electric motor as shown or operated manually. Fig. 2 is a partial side view showing the circuit breaker unit in the lowered position with the circuit breaker open and the driving clutch members engaged to effect elevation of the unit to the connected position shown in Fig. 1. Fig. 3 is a perspective view showing more clearly the detailed construction of the preferred form of clutch interlocked elevating mechanism with the clutch members engaged and the anticreep lock released. Fig. 4 is a circuit diagram schematically showing the improved reversing control circuit connections whereby the driving motor may be energized by means of the control switch closed when the clutch members are engaged only after a manually reversing switch is operated to select the proper elevating or lowering operation of the circuit breaker unit as predetermined by the limit switches. Fig. 5 is a side view of a special interlocking clutch type of manual operating crank adapted to cooperate with the improved clutch interlocked elevating mechanism when the driving motor is removed. Fig. 6 is an enlarged side View of a portion of Fig. l showing in greater detail the relationship of the breaker closing mechanism to the locking member during the time the breaker is in closed position. Fig. 7 is a view similar to Fig. 6 but showing the relationship of the breaker closing mechanism to the locking member during the time the breaker is open and blocked from closing by the locking member.

As shown in Fig. 1, a typical circuit breaker indicated generally by the reference character 16 is enclosed in a metal cubicle 11 with the breaker elevated to engage the disconnect contact plugs 12 extending from the top of the breaker with the stationary line connection terminals 13 inside the cubicle 11. The breaker 10 is elevated to and lowered from the connected position by means of the improved clutch interlocked form of carrier mechanism indicated generally by the reference character 14 and having the usual rotatable jack-screws 15 on each side of the breaker interconnected by roller chain 102 on sprocket 191 for raising and lowering a supporting frame 16 that is provided with suitable means for seating a supporting member 17 extending from each side of the breaker. The jaekscrews 15 can be driven by the reversible electric driving motor 18 through suitable force amplifying gear 19 mounted in the box 26.

The circuit breaker 10 may be of any suitable type but, as shown, is of the type illustrated and more fully described in the Spiro et al. Patent 2,445,190 assigned to the assignee of the present invention. As indicated by the dotted lines in Fig. l and shown more in detail in Fig. 6, the circuit breaker 10 is provided with a conventional trip-free closing mechanism, such as shown in Baskerville Patent No. 2,458,240, assigned to the assignee of the present invention. This mechanism includes a pivoted contact-actuating lever, or switch member, 20 that is connected through the link 21 to be operated by a suitable operating means such as a solenoid plunger 28 or the like. As shown in Figs. 1 and 6, the circuit breaker is in the circuit-closing position with the switch member 20 in the position in which the main circuit interrupting contacts of the breaker are closed. Such closing was effected in a well known manner by transmitting upward movement of the solenoid plunger 28 through the link 21 to rotate the switch member 20 clockwise about its stationary pivot 26a into the closed position of Figs. 1 and 6. The switch member 20 is latched in this closed position by suitable conventional means (not shown). The circuit breaker 10 is provided with a cam follower 22 that is fixedly mounted on a shaft 23 extending from the side of breaker 10 which shaft also has fixedly mounted thereon the locking member 24 that is operable to block closure of breaker 19 but is biased to the release position in which it is shown in Fig. 1 and Fig. 6 against the stop 25 by the spring 27. In this position, the link 21 in the closed position of breaker 1'0 engages with or blocks the locking member 24 so as to hold the locking member in the release position and also the cam follower 22 in the interlocking position in which it is shown in Fig. 1.

In accordance with the present invention, the circuit breaker carrier mechanism 14 is provided with driving clutch members 3% and 31 that are movable into engagement for operating the mechanism to carry the circuit breaker to and from the connected position in which it is shown in Fig. 1. One of the clutch members 36 is driven by the motor 18, and the other clutch member 31 is slidably mounted on a square end of shaft 32 that is mounted in box 26 and carries the high speed pinion 33 of the force amplifying reducing gearing 19 that drives the jack screws 15. The clutch member 31 is moved into engagement with the clutch member 30 by means of a manually operable channel lever 35 that is pivotally mounted on the fixed pin 36 and carries a pair of opposing pins 37 for engaging with the opposite sides of the groove 38 formed in the clutch member 31, so as to effect the necessary endwise movement of the clutch member 31 on square shaft 32 required to bring the clutch members 30 and 31 into engagement. Clutch engagement occurs in the following manner. When the lever 35 is operated in a counterclockwise direction from the position of Fig. 1, the clutch member 31 moves to the left in follow-up relationship thereto under the influence of a spring 100, which normally urges the right-hand wall of grooved portion 38 of the clutch member 31 against the pins 37. Fig. 2 shows the parts after this action has progressed to the point of clutch engagement and the lever 35 has been moved counterclockwise to the end of its operating stroke. It can be seen from Fig. 2 that sufficient lost-motion space is provided in the groove 38 to permit the pins 37 to move away from the right hand end wall of the groove when the clutch is engaged, thereby removing friction loads during operation. Should the jaws of the clutch members be out of alignment when the lever 35 is shifted into the position of Fig. 2, clutch engagement will be blocked by the jaws until the motor 18 starts. However, as soon as the motor starts and begins to rotate the clutch member 30, this misalignment will be corrected and the spring 100 will act to force the other clutch member 31 into meshing relationship with the clutch member 30.

A conveniently hooked manual operating handle 39 is provided for operating the lever 35 against the force of the spring 41 that normally biases the lever 35 to operate the clutch member 31 out of engagement with the clutch member 30 by sliding the clutch member 31 to the right to the position in which it is shown in Fig. 1. In this position, the notched creep locking disk 42 fixed to the clutch member 31 is moved into engagement with the cooperating creep lock member 43 that is slidably mounted in the box 26 and biased by spring 45 into engagement with the notches in the disk 42 so as to effectively lock the gearing 19 against movement and thereby insure against any accidental lowering of the circuit breaker due to jars or vibration, when the clutch members 30 and 31 are disengaged, as shown in Fig. 1. In the event that a notch in disk 42 is not in line with lock member 43 spring 45 will be further compressed. A very slight movement downward of circuit breaker 10 will cause disk 42 to rotate, aligning a notch with lock member 43 which will then snap into engagement with disk 42.

In order to interlock the engageable clutch member 31 and the locking member 24 for the circuit breaker closing mechanism so as to positively block and thereby prevent the engagement of the driving clutch members whenever the circuit breaker is closed, and also positively block and thereby prevent the closure of the circuit breaker whenever the driving clutch members are engaged, a cam plate 56 is siidably mounted on the carrier mechanism 14 inside the cubicle 11 by means of the bolts 51 so as to move in a vertical path adjacent the path of the circuit breaker it and is connected with the clutch operating lever 35 so as to be raised whenever the clutch members 35 and 31 are engaged. Thus, the pin 53 carried by the clutch operating lever 35 engages with a transverse slot formed in the upper end of the cam plate 50, for raising and lowering the cam plate 54'? 'When the clutch members are engaged and disengaged respectively. However, when the circuit breaker in is in the elevated position and is closed by operation of the closing lever 2x) to raise the link 21 to the position for holding the locking member 24 in the release position, the cam follower 22 is in position to engage with the cam face 50a and thereby effectively block and prevent the operation of the lever 35 to engage clutch member 31 with the clutch member 3'2 Consequently it is impossible to operate the circuit breaker carrier mechanism 14 as long as the circuit breaker remains closed.

But when the circuit breaker is tripped open, the closing lever 2b is rotated in a counterclockwise direction to the position of Fig. 7 to release the locking member 24. Then the operation of lever 35 to engage the clutch members will slide the cam plate 50 upwardly so as to engage the inclined face Stla with the cam follower 22 and thereby move the locking member 24 to the locking position shown in Fig. 7 against the bias of spring 27. In the position of Fig. 7, the locking member 24 would block clockwise closing movement of the closing lever 20. When the circuit breaker it? is lowered from the connected position, the cam foll wer 22 rides along the vertical face 5% of the cam plate 56 and thereby holds tr e locking member 24 in its position of Fig. 7 to block the movement of the circuit breaker closing lever 28 in the clockwise direction and thereby effectively prevent closure of the breaker until the cam follower 22 reaches the notch 590 formed in the cam plate 5%. When this test position is reached, the disconnect contacts 12 are fully disengaged from the circuit terminals 13 (as shown in Fig. 2) and hence the closure of the breaker can produce no harmful results. Thus, the notch 500 in the cam plate 59 permits the breaker to be tested in its lowered position and, if necessary, the breaker may then be removed laterally from the cubicle 11 through the door 11a for further inspection and repair or replacement. When the circuit breaker is replaced on the carrier mechanism 14 with the clutch members disengaged, the cam follower 22 will fall in the notch 50c whether the circuit interrupting contacts of the breaker are opened or closed. However, in case the breaker is closed, then the locking member 24 will be positively held in the re leased position, thereby positively holding the cam follower 22 in the notch 500. This will effectively prevent operation of the lever 35 to engage the clutch members 31 with the clutch member 32 until the circuit breaker 10 is opened.

With the circuit breaker open in its lowered or test position, the lever 35 can then be manually operated to move the clutch members 30 and 31 into engagement as shown in Fig. 2 to effect elevation of the circuit breaker 10. During such elevating operation, the cam follower 22 will ride along the vertical cam face 501) of the cam plate 50, thereby effectively blocking the circuit breaker closing mechanism to prevent closure of the breaker until after the disconnect contact plugs 12 are carried into engagement with the circuit terminals 13. As the circuit breaker 1t) approaches its fully connected position, the cam follower 22 will ride along the inclined cam face Stla so as to permit the locking member 24 to return to the release position in accordance with its bias, as shown in Fig. 1. Thereupon, the circuit breaker closing mechanism may be operated freely to close the main contacts of the breaker 10.

In order more effectively to control the energization of the reversible driving motor 18, the cam plate 50 is provided with an extension 60 for operating a control switch 61 that is connected in a reversing control for the motor 18 as shown in the schematic circuit diagram of Fig. 4. Thus, the clutch-operated switch 61 is connected in circuit with the two limit switches 62 and 63 that are located to be operated by the frame 16 at the opposite limits of travel thereof. A manually operable reversing switch 64 is provided for reversing the connection of the motor series field winding 18a with the armature winding so as to reverse the direction of rotation of the motor 18. The reversing switch 64 is biased to a midposition by the springs 65 and can be operated to the right into a lowering position, or to the left into a raising position, by means of a suitable manual operating handle 66.

Thus, when the reversing switch is moved to the right into the lowering position, operation of lever 35 to move clutch member 31 toward engagement will simultaneously close the control switch 61 and thereby establish a circuit extending through the closed limit switch 63, contact 67, to energize the operating winding of the relay 68 and thereby effect operation of the driving motor 18 in the lowering direction. As previously pointed out, if the jaws of the two clutch members are out of alignment when the clutch-operating lever is moved into its operated position of Fig. 2, then clutch engagement will be blocked by the jaws until the motor 18 starts. However, as soon as the motor starts and begins to rotate the clutch member 36, this misalignment will be corrected and the spring 104) will immediately act to force the other clutch menber 31 into meshing relationship with the clutch member 36). The fact that it is the operation of the clutchcontrol lever 35 which closes switch 61 to start the motor enables us to utilize the motor to aid in producing meshing of the clutch jaws in case of prior misalignment and also enables us to assure that this meshing relationship will be effected before the motor is brought up to speed. This assures that the clutch will be smoothly engaged without the risk of damage. After lowering the breaker, the limit switch 62 will become closed and limit switch 63 will be opened to effect deenergization of motor 18. Consequently, the reversing switch 64 must now be operated to the left into the raising position to energize the operating winding of relay 68, in order to produce a raising operation of the circuit breaker 10 when the lever 35 is operated to engage the clutch members 30 and and simultaneously close the control switch 61. It will be apparent that the control switch 61 also prevents disengagement of the clutch members under load, i. e., while the motor is energized. For example, when the parts are in the position of Pig. 2, it is necessary to rotate the actuating lever 35 clockwise through at least the arc subtended by the lost motion groove 38 before the pin 3'7 is effective to move clutch member 31 out of engagement with clutch member 3i). During this motion of lever 35 prior to clutch disengagement, extensio 60 would be moved downward and obviously cause the control switch 61 to open.

In case, for any reason, the driving motor 18 should require removal, then a special manual operating crank of the clutch interlocking type shown in Fig. may be employed for efiecting the raising and lowering operation of the carrier mechanism 14. This consists of a shaft 7 3 having a clutch member 30a formed to engage with the cooperating clutch member 31 and provided with a suitable operating crank handle 71. The shaft '70 also carries a thrust bearing 72, to which is attached an interlocking pin 73 for engaging with the notches 74 formed in the clutch operating lever 35, only when the lever 35 is manually operated to move the clutch member 31 into its normal engaging position. Thus, when the clutch member 30a is engaged with the clutch member 31 and the interlocking pin '73 is engaged with notch 47, the lever 35 will be maintained in its operated position while the crank 71 is rotated to effect either lowering or raising operation of the carrier mechanism 14.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. in combination, a disconnectable circuit breaker having a switch member and a closing mechanism coupled to said switch member, a locking member cooperating with said mechanism and having a locking position for preventing closure of the breaker and a released position for permitting closure of the breaker, blocking means positively coupled to said switch member for holding the locking member in said released position when the circuit breaker is closed, a carrier mechanism for the circuit breaker having driving clutch members movable into engagement for operating the mechanism to carry the circuit breaker to and from a connected position, and mechanical interlocking connections between one of the clutch members and the locking member for preventing engagement of the clutch members when the locking member is held in said released position by said blocking means and for moving the locking member to the locking position when the clutch members are engaged.

2. In combination, a disconnectable circuit breaker having a closing mechanism provided with a releasable locking member operable in a locking position to prevent closure of the breaker, a reciprocating carrier mechanism for the circuit breaker having driving clutch members movable into engagement for operating the mechanism to carry the circuit breaker in a linear path to and from a connected position, and interlocking means including a movable cam member connected with one of the clutch members to move in a parallel linear path and a cam followermounted on the circuit breaker and connected with the circuit breaker locking member for releasing the locking member only when the clutch members are disengaged, said cam member having a surface which extends parallel to said linear path and which acts through said cam follower to maintain said locking member in its locking position during movement of said breaker to and from said connected position.

3. In combination, a disconnectable circuit breaker having a closing mechanism provided with a locking member having a locking position for preventing closure of the breaker and means for holding the locking member in a released position when the circuit breaker is closed, and an elevator for the circuit breaker having driving clutch members movable into engagement for operating the elevator to raise and lower the circuit breaker to and from a connected position, and interlocking means including a cam plate mounted on the elevator and connected with one of the clutch members for vertical movement adjacent the path of the circuit breaker upon engagement of the clutch members and a cam follower extending laterally from the circuit breaker for engagement with the cam plate and connected with the locking member to hold the locking member in the locking position while the circuit breaker is raised and lowered and to block the vertical movement of the cam plate and thereby prevent engagement of the clutch members when the circuit breaker is closed.

4. In combination, a circuit breaker carrier mechanism, a reversible electric driving motor therefor having driving clutch members engageable for operating the mechanism and provided with a control switch closed only after relative movement of the clutch members toward engagement, and selective switching means for the motor including u selective two position reversing switch provided with a pair of auxiliary contacts each closed only when the reversing switch is in a corresponding position, a pair of limit switches, each operable at a corresponding limit of the carrier mechanism and an electroresponsive motor energizing switch having an energizing circuit interconnected with the control switch, the auxiliary contacts, and the limit switches to energize the motor only upon closure of the control switch after selective operation of the reversing switch to a corresponding position determined by each limit switch to operate the carrier'mechanism to th'e'oth'er limit.

5. A circuit breaker carrier mechanism having a dn'ving shaft and a driven shaft, a first clutch member mounted on said driving shaft, a second clutch member sl'id'ably mounted on said driven shaft for movement into and out of engagement with said first clutch member, a creep lock having a movable member mounted to lockingly engage said second clutch member upon disengagement 'of said clutch members and to release said second clutch member upon engagement of said clutch members.

6. In combination, a dis connec'table circuit breaker having a closing mechanism, a locking member movable between a release position and another operative position, said closing mechanism having a portion operable when the breaker is closed to hold said locking member in said release position and to positively block movement of said locking member out of said release position, a carrier mechanism for the circuit breaker having driving clutch members movable into engagement for operating the mechanism to carry the circuit breaker to and from a connected position, and mechanical interlocking connections between one of the clutch members and the locking member for preventing engagement of the clutch members when the locking member is held in said release position by said portion of the closing mechanism.

7. In combination, a circuit breaker carrier mechanism, a reversible electric driving motor therefor, means including jaw-type driving clutch members for operating the mechanism when said clutch members are engaged, means including a control switch operable to effect energization of said motor, clutch-control means operably interconnected to said control switch for effecting motor-energizing operation of said control switch in response to clutch-engaging operation of said clutchcontrol means, said clutch-control means acting to operate said control switch to energize said motor only after relative movement of said clutch members toward engagement.

8. The combination of claim 7 in which said clutchcontrol means is coupled to one of said clutch members by a lost-motion connection which permits slight additional movement of said clutch-control means in a clutchengaging direction if engagement of said clutch is blocked by misalignment of said jaw-type clutch members, and spring means effective after said additional movement for forcing said jaws into meshing relationship upon operation of said motor.

9. In combination, circuit breaker carrier mechanism, a reversible electric driving motor therefor, means including jaw-type driving clutch members for operating the mechanism when said clutch members are engaged, means including a control switch operable to effect deenergization of said motor, clutch-control means operably interconnected to said control switch for effecting motor-deenergizing operation of said control switch in response to clutch-disengaging operation of said clutchcontrol means, said clutch-control means acting to operate said control switch to deenergize said motor before said clutch members are disengaged.

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